1. Technical Field
The invention relates generally to audio systems, and more particularly to a system for spatially extracting the contents of an audio signal.
2. Related Art
Generating audible sound from an audio signal with a sound system is well known. The audio signal may be a pre-recorded audio signal or a live audio signal. Upon receiving the audio signal, the sound system may process the audio signal and typically provides an amplified form of the audio signal to a loudspeaker to generate audible sound. An example of a live audio signal would be a live stage performance with a singer and a band, such as an orchestra. An example of a pre-recorded audio signal would be a compact disc or electronic datafile on which a song of the singer and the band had been stored. Any other audio source may also be similarly provided.
Typically, compact disks, electronic datafiles and other forms of audio signal storage are made from a master recording of a source of audio, such as the singer and band performing in a studio or live concert venue. The singer and the band may perform using microphones, amplifiers, and recording equipment to receive and capture the live music being created by the singer and the band. During the recording, a sound mixing engineer may strategically position any number of microphones among the members of the band in order to receive the desired live sounds for recording. The recording equipment includes any number of input channels, configured to receive live audio inputs from the microphones and other instruments being played by the band.
The sound mixing engineer then mixes or adjusts the channels on which the audio signals were received to obtain a desired overall sound by the singer and the band. In addition, the sound mixing engineer may re-mix or otherwise adjust the recorded audio so as to designate how the recording will play back at a later time. For example, the sound mixing engineer may adjust the individual audio signals to make the position of the singer be perceived by listeners to be in a central location when the recording is played through the loudspeakers of an audio system, a violin be perceived as to the left side of the singer, and a guitar be perceived as to the right side of the singer.
Audio systems may also receive a two or more channel audio input signal, such as a stereo signal, and develop more output channels than the received input channels. Such audio systems include a system manufactured by Harman International Industries, Incorporated of Northridge Calif. that is known as “Logic 7™.” Such systems distribute the audio input signal to the output channels based on analysis of the phasing of the audio input signals with respect to each other.